Methanesulfonic Acid → Benzoxazole

HRID 1195203Notes

Reaction equation

HRID 1195203 reaction equation
Cl.Cl.N[C:4]1[CH:10]=[C:9]([NH2:11])[C:7]([OH:8])=[CH:6][C:5]=1O.[CH3:13]S(O)(=O)=O.O(C1C=CC(OC2C=CC=CC=2)=CC=1)C1C=CC=CC=1>>[O:8]1[C:7]2[CH:6]=[CH:5][CH:4]=[CH:10][C:9]=2[N:11]=[CH:13]1

Participants

4

Reactant 3

HCID 6395Methanesulfonic AcidHCID 520487Benzene, 1,4-diphenoxy-HCID 27336484,6-Diaminoresorcinol Dihydrochloride

Product 1

HCID 9228Benzoxazole

Conditions

Temperature
90 °C

Procedure

A mixture of 1.60 g (7.51 mmoles) of 4,6-diaminoresorcinol dihydrochloride and 3.32 g (11.26 mmoles) of oxy-bis(4-benzoyl chloride) is stirred under nitrogen atmosphere. A 10-1 methanesulfonic acid solution (89.7 g) is added. The mixture is heated for 2 hours at 70° C. and for 24 hours at 90° C. It is cooled to 50° C. and 0.98 g (3.75 mmoles) of p-diphenoxybenzene is added and washed down with 9.0 g of 10-1 methanesulfonic acid solution. Mixing is continued at 50° C. for 48 hours. The resulting copolymer is precipitated in a blender with aqueous sodium hydroxide, washed with water and dried to a constant weight. Its viscosity in concentrated sulfuric acid at 25° C. and a concentration of about 0.5 g/dL is about 0.96 dL/g.

Workup

  1. temperatureIt is cooled to 50° C.
  2. washwashed down with 9.0 g of 10-1 methanesulfonic acid solution
  3. additionMixing
  4. customThe resulting copolymer is precipitated in a blender with aqueous sodium hydroxide
  5. washwashed with water
  6. customdried to a constant weight
  7. customat 25° C.

Sources & evidence

ORD record
ord-d64a136235264780b230018cff93ab73
Source dataset
uspto-grants-1992_05
Patent number
US05110894

Reaction notes

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